Minimally invasive therapeutic surgical procedures are increasingly applied as alternatives to open surgical treatments. Exemplary minimally invasive surgeries, include transcatheter and laparascopic treatments and similar percutaneous surgeries. Such procedures are often guided by devices having a steerable or deflectable tip, or distal section, such as gastrointestinal endoscopes and myocardial injection or ablation guiding catheters. A conventional deflectable catheter typically has an elongate body and a flexible tip, or distal section, connected to the distal end of the body. One or more pull wires extend from the distal end of the tip to a control mechanism at the proximal end of the body. A control knob allows for selective pulling of the pull wires to cause the tip of the catheter to deflect in one or more directions.
Such classic (or “fixed-fulcrum”) deflectable-tip devices have limited degrees of freedom because the tips have fixed radii of curvature. In this regard, the length of the deflectable section of their distal tip mainly depends on the length of the distal deflection mechanism. In a myocardial injection catheter, for example, a fixed-fulcrum device would have limited ability to reach all myocardial walls from a single transaortic approach. Another drawback of the fixed-fulcrum design is that, because the tip, or distal section, has a fixed radius of curvature, navigating the device through a tortuous passageway within a body can be difficult.
Accordingly, there exists a need for new and improved guiding devices and methods for their use.